Launching device

ABSTRACT

A device in a lifting crane for releasing and recovering a load provided with a recovery cable comprises a lifting yoke having an aperture extending in a lifting direction of the lifting yoke, the recovery cable being slidable through the aperture; two locking members pivotally journalled in the lifting yoke about tangential axes of rotation, the locking members jointly capable of recovering and supporting a load while in a first position and, upon pivoting to a second position, releasing a supported load; and two regulating levers, one for each locking member, each regulating lever having a first end journalled on the axes of rotation of a respective locking member and a second end attached to a single biasing member, such as a spring interconnecting the pair of regulating levers, the pair of regulating levers, in combination with the spring, having an open position which forces the locking members to the second position for releasing a load and a closed position which, in combination with the spring, forces the locking members to the first position for recovering and supporting a load.

TECHNICAL FIELD

The present invention relates to a device in a lifting crane forlaunching and recovering a load provided with a recovery cable,preferably a remote-controlled seagoing vessel. The device comprises alifting yoke with through-holes in the direction of lift, through whichholes the recovery cable of the vessel may slide and in the walls of thelifting yoke, movable locking means which are pivotally disposed toretain or release a lifting device mounted in the vessel (load) at theend of the recovery cable.

BACKGROUND OF THE INVENTION

More precisely, the device according to the present inventionconstitutes an improvement to an older design and construction intendedfor the same purposes. This prior art design and construction (which isdescribed in Swedish patent No. 8703471-6) is, thus, intended for thelaunching and recovery of loads provided with recovery cables, such asremote-controlled seagoing vessels. In this instance, it comprises alifting yoke provided with a through-hole in the direction of lift forthe recovery cable and a number of pivotal locking means disposed toretain or release a lifting device mounted in the vessel at the end ofthe cable. However, in this design and construction the lifting yoke isoperated by means of a first set of lines or wire ropes, while thelocking means, which are pivotal about tangentially disposed shafts, areoperated by means of a second set of lines or wire ropes secured inlever portions extending outside the lifting yoke and included in thelocking means.

For switching this construction from the launching to the recoveryposition, displacement is necessary of the anchorage points of both setsof lines in relation to the lifting ring. As a result, this has beendesigned with an elongate portion along which the anchorage of the linesregulating the locking means may be displaced and manually locked in twodifferent positions, one of which is the launching position and theother is the recovery position. In addition, it is necessary that thelocking means, in connection with preparation for launching, aremanually switched to the locked position before lifting of the seagoingvessel is activated in connection with launching. On the other hand,this design and construction affords the advantages of not requiring anycontrolled switching of the locking means when the vessel reaches thesurface of the water during the launching process proper or during therecovery operation. The reason for this is that, during these operationsequences, the devices functions fully automatically as a result of thedesign of the locking means and the line anchorages.

Given the severe environments which this device is intended to operateincluding freezing temperatures and also given the risk of powerfulcorrosive attack, it has now been considered necessary within the art tosimplify the switching from launching position to recovery position tothe simplest possible manual operation and, in addition, to eliminatethe potential risks of functional disturbance residing in the fact thatthe locking means are switched from the open position as a result offorce of gravity in the form of simple ballast weights placed outermoston the lever portions of the locking means.

SUMMARY OF THE INVENTION

It has now proved possible through the present invention to satisfythese conditions in that the previous unlocking and locking functioncontrolled by the cable of the locking means and by force of gravity hasbeen replaced by a "spring bolt" readily switchable between launchingand recovery positions and which has no loose parts. As a result of thisdesign and construction modification, we have, moreover gained theadvantage that the entire device has become considerably smaller,because it operates vertically in the recovery phase. Like the prior artdesign, this new device also operates fully automatically in bothlaunching and recovering the vessel in question.

In the above-discussed prior art construction, the lifting ring wasfurther designed as two separable halves in order to make it possible topass in the recovery cable of the vessel from one side into athrough-channel intended for this purpose. This separation possibilityhas now been replaced by a vertical groove running through the liftinghousing in whose inlet portion a "port" in the form of a cylindricalrotary sleeve also provided with a groove is disposed. The recoverycable of the vessel may, thus, be moved from the side into the groove inthe lifting housing to the innermost portion of the groove of thesleeve, whereafter the sleeve is rotated such that the recovery cable islocked in its groove. This design realizes a more stable and moreresistant lifting unit than the prior art separable variation. Therotary sleeve may, for example, be produced from the plastic materialacetal.

According to the present invention the locking means pivotallyjournalled about tangentially applied axes of rotation are united bymeans of a regulation function in the form of a spring-biasedinterconnection which, in response to the adjustment setting of theregulation function, actuates the locking means towards open positionfor launching and closed position for recovery, respectively, and it ispossible, irrespective of the selected adjustment setting of theregulation function to force the locking means by the weight of thecargo or load and against the action of spring force over to theopposite position in order to be returned to the originally set positionby spring force as soon as this actuation ceases.

In such instance, the regulation function preferably consists of twolevers which are journalled with their inner ends in the axes ofrotation of each respective locking means about transverse shaftsdisposed transversely of these axes of rotation and between whose freeouter ends a drawing spiral spring is tensioned, while the locking meansare fixedly secured at their axes of rotation, which in turn are movablyjournalled in the lifting housing. The levers and the locking means thustogether form a rotationally rigid unit in which the angular positionsof the levers in relation to the locking means may be varied between twoend positions which make an angle of 180° with each other.

The switching operation between launching and recovery positionsproceeds such that both of the levers are simultaneously rotated through180° about their respective transverse axes. This implies that thespring loading for the rotation of the locking means for the rotationchanges direction.

In order to prevent unintentional switching of the levers between thelaunching and recovery positions while the vessel is suspended in thelifting yoke, there are provided special locking devices which amautomatic and cannot be cancelled out, for reasons of safety.

It is also conceivable to introduce locks which permit a switching ofthe levers only after a predetermined force has actuated them. In thelocking devices which are currently under consideration, the switchingfrom launching position to recovery position once the vessel hasdeparted from the lifting yoke may be remote-controlled by means of acable connection which, when it is stretched in the direction of thelifting cable, forces the levers to the upper position, i.e. to theposition which corresponds to recovery position.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention has been defined in the appended claims and willnow be described in greater detail hereinbelow, with particularreference to the accompanying drawings. In the accompanying drawings:

FIG. 1 is an overall illustration of the device seen from the side ofthe vessel;

FIG. 2 is a section through the device with cable and lifting device;

FIGS. 3-5 schematically illustrate three phases during recovery;

FIGS. 6-8 schematically illustrate three phases during launching;

FIGS. 9-10 show the function of the port;

FIGS. 11-12 show the parts of the vessel and their function duringrecovery; and

FIGS. 13-14 show the parts of the vessel and their function duringlaunching.

In the figure, corresponding parts are, to the extent they are includedin the illustrations, provided with corresponding reference numerals.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The device illustrated in FIG. 1 and others consists of the liftinghousing or lifting yoke 1 which is suspended in two lifting cables 2 and3 collected in a lifting ring 4 of which only a part is shown on thefigure. Through the lifting ring 4 there also runs an operating cable 5to which we shall return later.

In the lifting yoke 1, two locking members 6 and 6' are furtherpivotally journalled with their respective axes of rotation 7 and 7'with which they each form their rigid construction. In the shaft ends ofthese axes of rotation projecting out through the wall of the liftinghousing 1, two levers 9, 9' are rotatably journalled in grooves 8, 8' ineach respective shaft end about transverse shafts 10, 10'. Rotation ofthe levers 9, 9' is 180°, i.e. in the illustrated example with thelevers turned to face upwards or downwards. The free outer ends of thelevers are united by means of a drawing spiral spring 11. As isprimarily apparent from FIGS. 11 and 13, the shafts 10 and 10' make acertain angle with the longitudinal direction of the levers, i.e. theapertures through the levers intended for the shafts do not run at rightangles through the levers. This is to give the levers the best angle intheir respective positions. Consequently, the grooves 8, 8' have thespecial cross design shown on the figures which gives the leversabutment against the edges of the grooves only at those parts where theaction of the spring 11 may be directly transferred to each respectiveaxis of rotation 7, 7'.

Two arrest heels, 12, 12' are also provided in the lifting yoke andlimit the movements of the locking members 6, 6' in the openingdirection. In the closed position, the locking members abut with theirrear ends, i.e. those ends which do not account for the lockingfunction, against fixed abutment 13, 13' in the lifting yoke 1.

As was shown in FIG. 1 and in greater detail in FIGS. 11-14, thedownwardly directed position of the levers is designated "launch" andtheir common upwardly directed position carries the designation"recover".

In order to lock the levers 9, 9' in the launch position until launchinghas been carried out, there are two resilient locks 14, 14' to which wewill revert later. Mention was made earlier of the operating cable 5which, via a cable connection 15, is connected to the free outer ends ofthe levers and is utilized for forcing over the levers 9, 9' from"launch" position to "recover" position.

A through aperture 16 runs through the lifting yoke 1 for the recoverycable 17. This latter is terminated in a lifting device 18 which isfixedly secured in the relevant load 19. The lifting devices in the formof a truncated cone whose smallest defining surface is turned to faceupwardly. The aperture 16 is in the form of a groove open to one side.Around the groove and in the proximity of its inlet side, a cable portis provided in the form of a rotary sleeve 20, in the present caseproduced from acetal plastic. A groove 21 is similarly provided in thissleeve for the lifting cable. When the lifting cable is to be moved intoplace, the sleeve 20 is rotated so that its groove 21 is turned to faceoutwardly, the cable is moved into the groove 21 whereafter the sleeveis rotated through 180° and the cable is in place (see FIGS. 9 and 10).

When the device has been made ready for launching, the recovery cable 17is in place in the groove or the aperture 16, the levers 9, 9' are inthe "launch" position, i.e. turned to face downwardly and the liftingdevice 18 loads the locking members 6, 6' so that their rear portionsabut against the arrest abutment 13, 13', i.e. the locking members arein the closed position even though the levers 9, 9' load the lockingmembers to urge them in the opening direction. (See FIGS. 6-8 and 13,14). As soon as the load reaches the water, the locking members areunloaded and the spring 11 draws the levers towards one another,whereupon the locking members open. As soon as the recovery cable 17 isreleased, contact between the load and the lifting yoke will then cease.

For this to operate, there must, thus, be clearance between the cone ofthe lifting device 18 and a corresponding cone in the lifting yoke, seeFIGS. 5 and 13. Space available therebetween must be sufficient to allowthe locking members to move away from the cone when this lifts.

By loading the cable 5, the device may now be switched to the recoveryposition. The levers 9, 9' are then switched over into "recover"position, i.e. facing upwards. In this instance, the locking members 6,6' are influenced by the spring 11 in the closing direction (see FIGS.3-5 and 11, 12). When the load reaches the lifting yoke 1 and therecovery cable 17 is tightened, the locking members are loaded by theupper portion of the lifting device 18 which, against the action of thespring 11, forces up the locking members so that the lifting device maypass. As soon as this has taken place, the locking device is closed,whereafter the load may be recovered simply by utilizing the liftingcables 2 and 3 of the lifting yoke and without any further loading ofthe recovery cable 17.

What we claim and desire to secure by Letters Patent is:
 1. A device ina lifting crane for releasing and recovering a load provided with arecovery cable, said device comprising:a lifting yoke having an apertureextending in a lifting direction of said lifting yoke, said recoverycable being slidable through said aperture; two locking memberspivotally journalled in the lifting yoke about tangential axes ofrotation, said two locking members jointly capable of recovering andsupporting a load while in a first position and, upon pivoting to asecond position, releasing a supported load; and two regulating levers,each for controlling one of the locking members, each regulating leverhaving a first end journalled on the axis of rotation of a respectivelocking member and a second end attached to a single biasing meansinterconnecting said pair of regulating levers, wherein said pair ofregulating levers, in combination with said biasing means, when in anopen position, forces the locking members to said second position forreleasing a load and when in a closed position, forces the lockingmembers to said first position for recovering and supporting a load. 2.The device according to claim 1 wherein said locking members, whilereceiving a lifting anchor of said load in said first position, areforced partially open by said lifting anchor against action of thebiasing means until said load reaches a support location at which timethe locking members spring back into said first position.
 3. The deviceas claimed in claim 1 wherein said regulating levers are jointlyswitchable between said open and closed positions by rotation abouttheir respective transverse axis.
 4. The device as claimed in claim 1wherein said aperture for the recovery cable comprises a rotary groovedsleeve rotable between a first position, in which said recovery cablecan be installed in said aperture and a second position in which saidrecovery cable is secured in said aperture.
 5. The device as claimed inclaim 1 further comprising locks in said lifting yoke for preventingsaid regulating levers from moving from said open position until theload has left the lifting yoke.
 6. The device as claimed in claim 1wherein said second ends of said regulating levers are connected to acable which, when tightened, forces the levers from said open positionto said closed position.
 7. The device according to claim 1 wherein saidbiasing means is a drawing spiral spring.